The invention relates to a one-sided corrugated cardboard machine comprising a machine stand, an upper and a lower fluted roller as well as a pressure roller cooperating with the lower fluted roller and pivotably supported on lever arms at the machine stand, adjustable abutments at the machine stand associated with the lever arms, and adjusting means supported at the machine stand and cooperating with the lever arms, said adjusting means pressing the lever arms against the abutment surfaces in order to adjust the pressure roller nip.
Such one-sided corrugated cardboard machines have been known for a long time. The lower fluted roller is fixedly supported with respect to its axis of rotation in the machine stand, while the upper fluted roller is pivotably supported at lever arms and is pressed against the lower fluted roller with the aid of a pneumatic or hydraulic arrangement. The pressure roller is likewise pivotally supported at lever arms. But the pressure roller cannot be readily pressed against the lower fluted roller because this would entail a so-called stumbling run owing to the running-off movement of the corrugation of the fluted roller on the cylindrical pressure roller. For this purpose, abutments are provided at the machine stand which delimit the movement of the pressure roller onto the lower fluted roller. The abutments are adjustable in order to adapt the width of the nip to the thickness of the paper. With the aid of a hydraulic or pneumatic contact pressure means the levers which are extended beyond the bearing point of the pressure roller are pressed in a direction towards the lower fluted roller.
The known construction, however, suffers from certain disadvantages. The contact pressure means must press the lever fastly against the abutments so that even with greater forces effective in the roll nip the latter will not be widened. For this purpose a contact pressure means is required which must be designed for great forces. Even if it is formed by hydraulic pressure cylinders, a certain yieldingness cannot be avoided. Therefore, there is a danger of a certain oscillation of the lever arms in dependence upon forces occurring in different degrees in the roll nip. Such an oscillation, however, is undesirable for several reasons. It may impair the quality of the paper. Furthermore, noises will be created in a substantial degree. Also the roller lifetime will be negatively influenced thereby. Finally, with greater forces, the levers supporting the pressure rollers may experience a certain deflection thereby impairing the accuracy of the roll nip.
It is the object of the innovation to counteract such disadvantages and, in particular, to provide a bearing means for the pressure roller enabling an especially quiet run of the pressure roller.